Variations in the crab diversity of the mangrove environment from Tamil
Nadu, Southeast coast of India
S. Ravichandran & F.S. Wilson
Centre of Advanced Study in Marine Biology, Annamalai University, Parangipettai-608502, Tamil Nadu, India.
E-mail: sravicas@gmail.com
Abstract
The macro benthic faunal composition in the mangrove forest is diverse. Crabs are the most
dominant species in many mangrove forests which constitute about 80% of the macro faunal
biomass. Biodiversity of crabs in eight different mangrove environment of Tamil Nadu was
investigated for the first time. Maximum number of crab species (46) was recorded in the
Pichavaram and minimum (4) in Punnakayal mangroves. Two families of the crabs Grapsidae
and the Ocypodidae are particularly associated with mangrove ecosystem. Among the crab
species Sesarma and Uca species were dominant in almost all the stations. Grapsid crabs
were the most dominant species. Neritic and Avicennia zones showed more number of crab
species but less number of species was noted in slightly saline zone. The substrate suitability,
tidal inundations and mangrove distribution were the possible factors for distribution of crabs
in Tamil Nadu mangroves.
Keywords
species composition, zonation, distribution, population density, biosphere
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